Computer Simulation of Thermal Annealing Effects on Self Implanted Silicon

1994 ◽  
Vol 373 ◽  
Author(s):  
G. DE Sandre ◽  
L. Colombo ◽  
D. Maric

AbstractWe investigate the effects of thermal annealing on the structural, elastic and electronic properties of self implanted silicon by tight binding molecular dynamics. The irradiated samples, after a careful relaxation at room temperature, are annealed at different temperatures and for different times and, finally, their properties are carefully monitored during constant temperature simulations. We further provide a characterization of the chemical bonding in the amorphous network and show the evolution of the point defect distribution against maximum annealing temperature.

1993 ◽  
Vol 321 ◽  
Author(s):  
D. Maric ◽  
L. Colombo

ABSTRACTWe present an investigation on the amorphization process of crystalline silicon induced by ion beam bombardment by simulating the insertion of self-interstitials at different temperatures. The simulation is carried out by tight-binding molecular dynamics which allows for a detailed characterization of the chemical bonding and electronic properties of the irradiated samples. The irradiation process consists of two steps: (i) insertion of defects at a constant rate; (ii) annealing of the sample and observation of its structural properties. Thanks to the large size of the simulation cell (up to 276 atoms) we can characterize the amorphous network both on the short-range and Medium-range length scale. Electronic properties are investigated as well and their evolution is monitored during the insertion process. Finally, we present a thorough comparison of the structural properties of the irradiated sample with amorphous silicon as obtained by rapid quench from the Melt.


1993 ◽  
Vol 321 ◽  
Author(s):  
C. Molteni ◽  
L. Colombo ◽  
L. Miglio

ABSTRACTWe investigate the short-range structural properties of a-GaAs as obtained in a computer experiment based on a tight-binding molecular dynamics simulation. The amorphous configuration is obtained by quenching a liquid sample well equilibrated at T=1600 K. A detailed characterization of the topology and defect distribution of the amorphous network is presented and discussed. The electronic structure of our sample is calculated as well. Finally, we discuss the reliability and transferability of the present computational scheme for large-scale simulations of compound semiconductor materials by comparing our results to first-principles calculations.


1993 ◽  
Vol 316 ◽  
Author(s):  
D. Maric ◽  
L. Colombo

ABSTRACTWe present an investigation on the amorphization process of crystalline silicon induced by ion beam bombardment by simulating the insertion of self-interstitials at different temperatures. The simulation is carried out by tight-binding molecular dynamics which allows for a detailed characterization of the chemical bonding and electronic properties of the irradiated samples. The irradiation process consists of two steps: (i) insertion of defects at a constant rate; (ii) annealing of the sample and observation of its structural properties. Thanks to the large size of the simulation cell (up to 276 atoms) we can characterize the amorphous network both on the short-range and medium-range length scale. Electronic properties are investigated as well and their evolution is monitored during the insertion process. Finally, we present a thorough comparison of the structural properties of the irradiated sample with amorphous silicon as obtained by rapid quench from the melt.


2015 ◽  
Vol 1 ◽  
pp. 8 ◽  
Author(s):  
Juan Huguet-Garcia ◽  
Aurélien Jankowiak ◽  
Sandrine Miro ◽  
Renaud Podor ◽  
Estelle Meslin ◽  
...  

2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.


1991 ◽  
Vol 69 (3-4) ◽  
pp. 451-455 ◽  
Author(s):  
H. Lafontaine ◽  
J. F. Currie ◽  
S. Boily ◽  
M. Chaker ◽  
H. Pépin

Tungsten thin films are deposited with a triode sputtering system in order to obtain an absorbing layer for X-ray masks. The mechanical stress is studied as a function of different pressure and RF power conditions during deposition. Rapid thermal annealing at different temperatures and durations is performed in order to produce films under low compressive stress. We observe that the stress changes occur over the time scale of seconds at the annealing temperature and that the corresponding activation energies are low (60 meV). Grain growth in a preferred orientation explains the observed changes in stress. The magnitude in the change of stress is in good agreement with a model proposed by Hoffman et al. relating the stress to grain size and grain boundary dimensions. [Journal translation]


2020 ◽  
Vol 22 (26) ◽  
pp. 14630-14636
Author(s):  
Rong Cheng ◽  
Wen-Cai Lu ◽  
K. M. Ho ◽  
C. Z. Wang

We have performed tight-binding molecular dynamics simulations to study the structures and properties of liquid carbon with the density ranging from 1.4 to 3.5 g cm−3, and identified three liquid carbon phases at different density regime.


2005 ◽  
Vol 19 (15n17) ◽  
pp. 2804-2810 ◽  
Author(s):  
LEI MIAO ◽  
SAKAE TANEMURA ◽  
YASUHIKO HAYASHI ◽  
MASAKI TANEMURA ◽  
RONGPING WANG ◽  
...  

ZnO nanobamboos and nanowires with diameters of 10–30 nm and lengths of 2–4 μm have been prepared by laser ablation in vacuum with precisely controlled pressure, growth and post-annealing temperature. XRD results show the annealed sample is hexagonal ZnO . Low-magnified TEM observation reveals the annealed sample includes ZnO nanobamboos and nanowires. High resolution TEM image and electron diffraction pattern confirm that the structure of ZnO nanobamboo is regular stacking of Zn and O layers with high crystal quality. The growth direction is determined as along [001] direction (c axis). TEM observations confirm that the formation of bamboo-shape ZnO is due to the stacking fault and cleavage. The bundle of those stacking faults seems to be the origin of the black contrast at the nodes. The uniformity of chemical composition for the nanobamboos is identified by EDS profiles. A strong-narrow UV band centred at 390 nm and a weak-broad green band centred at 515 nm are observed at room temperature in the PL spectrum recorded from the annealed ZnO nanobamboos and nanowires.


2013 ◽  
Vol 663 ◽  
pp. 381-386
Author(s):  
Chi Shiuan Yen ◽  
Huai Yi Chen ◽  
Horng Show Koo ◽  
Chiung Hui Lai

In this paper, we used RF sputter to deposit the ZnO seed layer of 0.6 μm in thickness, which was then immersed in zinc nitrate hexahydrate [Zn(NO3)2•6H2O] and hexamethylenetetramine (C6H12N4) mixture solution of different concentrations for the growth of ZnO nanorods by hydrothermal method. After annealing at different temperatures, thermal field emission scanning electron microscope (TFSEM) was used to observe the arrangement and growth of ZnO nanorods. We found the concentration of the mixture solution of C6H12N4 and Zn(NO3)2•6H2O would affect the thickness and crystallization of ZnO nanorods, and the annealing temperature would change their columnar arrangement structure. The arrangement structure of the ZnO nanorods grown in the mixture solution of 0.2M concentration had more gaps and pores. Under this condition, we successfully fabricated a dye-sensitized solar cell (DSSC), of which the performance could be further improved by using ZnO nanorods prepared by many different methods.


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